Circuit maker and breaker



N 7, 1950 F. TALBOT 8,

CIRCUIT MAKER AND BREAKER Filed Dec. 12, 1946 3 Sheets-Sheet 1 FIG. IF|G.2

INVENTOR FRANK A. TALBOT,

Nov. 7, 1950 F. A. TALBOT 2,523,922

CIRCUIT MAKER AND BREAKER Filed Dec. 12, 1946 s Sheets-Sheet 2 FIG. 3FIG. 4

sow X 2 52- a 47 46 l o '48 52- 50 46 l 5a 54 49 5s 54 49 INVENTOR FRANKA. TALBOT,

7*" ATTORNEYO Nov. 7, 1950 F. A. TALBOT 2,528,922

CIRCUIT MAKER AND BREAKER Filed Dec. 12, 1946 3 Sheets-Sheet} .04magic-1.9 QFIG.IO

Zmventor FRANK A. TALBOT,

Patented Nov. 7, 1950 CIRCUIT MAKER AND BREAKER Frank A. Talbot,Baltimore, Md., assignor of onehalf to Robert E. Barry, Washington, D.0.

Application December 12, 1946, Serial No. 715,668

'9 Claims.

This invention relates to improvements in circuit makers and breakers,and more particularly to a snap-action lighting switch of ruggedconstruction which provides safety, dependability, minimum maintenanceand positive operation for use in locations where atmospheric conditionsare adverse.

One of the objects of the invention is to provide a novel snap-actionmechanism applicable to various kinds of switches.

A further object is to supply a lighting switch, the contacts of whichmay be immersed in oil, and a switch provided with novelthermostatically-controlled means for short circuit and overloadprotection.

Another object of the invention is to furnish a switch of this characterhaving an operating lever of trim design, but large enough to provide agood, comfortable grip assuring positive and easy operation, and onewhich may be used to indicate the electrical position of the switch solong as the thermostatic control is in a certain position.

A further object is to supply the switch with renewable contactsheavyduty, series break. This large contact area and series break preventsthe concentration of burning. In accordance with theinvention, thecontacts are self-aligning-constant pressure.

A still further object is to provide a snapaction switch including acontact actuator, that is constantly urged to open-switch position, butnormally held in closed position by a thermostatically-controlled latch.

With the foregoing objects outlined and with other objects in view,which will appear as the description proceeds, the invention consists inthe novel features hereinafter described in detail, illustrated in theaccompanying drawings, and more particularly pointed out in the appendedclaims.

In the drawings:

Fig. 1 is a side elevation, partly in vertical section, of oneembodiment of a switch in accordance with the invention.

Fig. 2 is a rear elevation of the same.

Fig. 3 is a front elevation with the switch in .closed position and withthe thermostaticallycontrolled latch in latched position. Fig. 4 is aview like Fig. 3 with a front cover removed and showing the switch inopen position and the thermostatic latch in unlatc'hed position.

Fig. 5 is a front'elevational'view of a modiflcation of the snap-actionmechanism shown.

connected to an operating means and a contact carrier, with parts brokenaway to facilitate illustration. In this view, the switch is shown inclosed position.

Fig. 6 is a top plan view and Fig. 7 an end view, respectively, of thestructure shown in Fig 5.

Fig. 8 is a view similar to Fig. 5 but showing the switch in openposition.

Fig. 9 is an end view and Fig. 10 a side elevation, respectively, of apin forming part of the mechanism illustrated in Figs. 5 to 8,inclusive.

Referring to the switch illustrated in Figs. 1-4 of the drawings, Illdesignates a panel of insulating material adapted to be fixedly arrangedin an upright position in any suitable casing (not shown), so the lowerportion 0f the mechanism may be immersed in oil.

A cover or face plate II is positioned forwardly of the panel and isrigidly connected with spacing arms [2, detachably secured to the panelby means of screws l3 or the like. The arms act to rigidly support theplate II and to space it from the panel.

A horizontal rock shaft [4 is journalled in the face plate and providedat the front end thereof with an operating lever l5, of trim design, butlarge enough to provide a good grip to assure positive and easyoperation of the shaft. Such handle may be employed with indicia (notshown) on the plate I I to indicate whether the switch is open orclosed.

A toggle actuator I6 is fixed to the shaft and is provided at its topwith a nose or cam IT to engage and cooperate with pairs of toggle linksl8 and IS. The links'l8 are fulcrumed at one end on a fixed pivot 20supported by the plate II, and the links [9 are pivotally mounted at oneend on a fixed pivot 2|, also supported by said plate. The opposite endsof the links are pivotally connected respectively at 22 and 23 toopposite lateral arms 24 and 25 of a three-armed lever 26. The lever hasa centrally disposed slot 21 for the reception of a stud 28 whichprojects forwardly from the upper end of a contact carrier or actuator29. The stud is pivotally connected to the part 29.

The third or upwardly extending arm 30, of the three-armed lever, isconnected to one end of a coil spring 3|, the opposite end of which isanchored to the top portion of the plate ll so that the spring acts tomove the three-armed lever either in clockwise or counter-clockwisedirection after the arm 30 has swung either to the left or right afterpassing dead center, in pivoting on the stud or pin 28. The latter isfixedly mounted on the upper end of a substantially triangular lever 32,rotatably supported on the shaft it. As the pin 28 extends into the slot21, it will be obvious that each time the three-armed lever 25 isshifted, the pin 28 will also be shifted either to the right or left,and in order to insure snap-action, a coil spring 33 surrounds the shaftl4 and has-its ends extending into notches 34 and 35 of the respectiveforward'extensions 35 and 31 of the actuator l6 and the lever 32.

The medial portion of the contact carrier 29 is pivotally connected to astud 38 which projects entirely through the contact carrier and forms alatch element 39 at-the front thereof (Fig. 1). The opposite end portionof the stud 38 extends through a hole 40 oflargerdiameter than the stud,in the panel l0, and is fixedly connected to an oscillating member orsupport ll, pivotally mounted at 42 on the rear of the panel. A. ,coi1.spring .43 (Fig. ,2) hasone ,of its endsanchored to theoscillating..memb.er, at 44 andits opposite end anchored-to a fixedterminal 45 at the rear of the panel. Due to'this,cons truction, thespring lfi tends to... constantly move the contact carrier 29in aclockwise direction (Fig. 12)

about the fulcrum pin "28, from which the con-.

tact carrier is suspended.

'The contact carrier 29jfixe'dly carriesat its.

lower.end, a bracket .46'having an. aperture .to slidably receive ashaftor rod 4'! havinga head 48 atone end to'limit "the movementof thebracketin one direction. .A contact bridge .49 is loosely mounted ontherod between a cotter pin 0,,extending through a, hole in the rod. anda.coil spring .5l that abuts, at one end against the bracket 86 andatthe otherend, against the bridge. The rod also moves axially in aguide hole extending through a "bracket 52 held in placebycylindricalpontacts 53and 54,, removablyfixed to the front of thepanel andarranged atright angles thereto. The bracket 52 is ofinsulating material so that currentcannot pass from the lead-in contact54to the contact 53 whenthe switch is ,open, but, whenit is closed,allowsthe current tofiow from 54 through the bridge 49 to the contact53.

Astud 55 is'fixed to the front'ofthe panel, to bev contacted by thelower end of the contact carrier .29 to limit opening movement of theswitch.

A bi-metallic or thermostatic element has'legs 56 andE'! connected to alower transparent face plate .58 (supported bythe contacts 53-54). asshown in Figs. 1, 3 and 4, and the leg 56 is in electricalconnectionwith-the contact 53. These legs are of L-shape (Fig.1) with curvedportions 59 arranged adjacent the bends therein and the horizontalportions 60 of the legs-are connected to one anothenas indicated-attl..The linking portionfil of the bi-lnetallic element carries a dependinglatching elementi62, cooperating with thelatching element 39 to hold thecontact carrier129 in a.certa in position solong as the bimetallicelement is in normal position, ,or the fullline position shownin'Fig. 1. When the thermostatic element is affected by conditions inthe line, heat ,willcause the part 6! to rise to the dottedlineposition(Fig. 1), so that the part 62, will release thelatch element 39 andallow the spring 43 toshift the. contact carrier to openswitch position,as indicated in Fig. 4.

Current. leaves the switch througha terminal 63 in electric contact withthe legs5l of the thermostatic element.

In operation, assuming that the switch is closed, as indicated in Fig.3, and the thermostatic latch element 62 is in engagement with the latchelement 39 of the stud 38, on which the contact carrier 29 pivots, ifthe operating member or handle I5 is moved counter-clockwise, the noseor cam U will engage and raise the ends of the toggle links [8 whichturn counter-clockwise about the pivotzpoint 20. At the same time, theactuator IS, in m'ovingcounterclockwise, will act by means of itsextension 36 onone leg of the spring 33, to tension the latter while themember 32 remains stationary. As soon as the-pivot point 22 risessufficiently to turn the arm 30 of the three-armed lever clockwise,beyond. deadcenter, the spring 3! will act to throw the arm 30 into theposition shown in Fig. 4, and

as the'toggle mechanism snaps into position, to placexthe axis of thepivot 23 below the axis of the pivot 22, the spring-33 will recoil sothat oneofitsdegs will act on the extensiont'l, of the member 132 toturn the latter-counter-clockwise. Asthemember 32 carries the pin.28,'that pin willact-to move the upper end of the contact carrier .29toward the left, and as the central portion ofthe contact carrier pivotson the stud 38, it is obvious that the bracket 46 will act on thehead430i theshaft 41 to move the bridge 49,away. from the contacts53 and.54.

If the handle l5'is now turned in a clockwise direction, an oppositeaction will take place so as to closethe switch.

While the switch is closed, if any disturbance inlthe circuit shouldcause the bi-metallic memberto act to raise the latch element62, thecontact carrier 29 is automatically turned counterclockwise about thepivot'28 to open the switch. Thisaction maybe readily. understood fromFig. 2 where it may be'seen that 'the 'pin'38, if not held inthefullline position by the thermostat,

willibe caused bythe spring l3, to travel with the member .41counter-clockwise about the'pivot 42 so asto shift the contact carrieraboutthe pivot 28 until the, lower end of. the contact carrier .ishalted by the stop. 55. 7

As long as thethermostatic element isin the dotted line position shown;in'Fig. 1, the latch cannot function and hence eventhough thesnapaction mechanism at the upper end .portion of the deviceisjactuated, it will'have ,no effect on opening or closing of the switchbecause the stop 55 will then function as a fulcrum,'and 'the'contactcarrier will'simplyturn aboutthis fulcrum when the pin 28' ismoved'towardithe right or towardthe left.

In Figs. 5 to 10,. inclusive, I have illustrated thesnap-action'mechanism-as usedfora large safety switch. This is similarto the'switch disclosed in'Figs. 1 to {Linclusive except for thelatching spring and center pin-of toggles. In Figs. 5 to 10, 10indicates a mounting panel through which a horizontal pivot bolt Hextends. An actuating plate 1.2 ispivotally mounted thereon rearwardlyof .thepanel, and provided with a rearwardlyextending horizontal pin"'l3to which is attached a vertically reciprocating. handle or. operatingmember 14, employed in oscillating the actuation plate 12 vertically onthe bolt.

Arranged at the front of the panel and also pivotally mounted. on thebolt, is a driven plate 15.. Theactuatingplate .12is provided withanarcuate slot 16 arranged concentric to the axis of the bolt.

Theplate 15 is provided witha projecting ear 1'! in which is journalleda pin 18 (Figs. 9 and 10) having end portions I9 provided withoppositely disposed flat sides 80. The fiat sided ends of the pivot pinextend into straight slots 8I provided in front and rear three-armedlevers 82 and 83, spaced apart and connected together by pivot pins 84,85 and 86. A toggle link 81 has one of its ends connected to the pin 84and its opposite end pivotally connected to a stationary horizontal stud88 mounted upon the front of the panel I8. Another toggle link 89 hasone of its ends pivotally connected to the pin 86 and its other endpivotally connected to a fixed stud 90 projecting from the panel ID.

A slidable stud 9| is pivotally connected to the pin 85 and slides inguide bracket 92 fixed to the front of the panel. A coil spring 93surrounds the stud and serves to act upon the three-armed levers 82, 83so as to hold the toggle mechan sm in either of its two positions, afterit passes dead center. A horizontal stud 94, fixed to the lever 83,projects rearwardly therefrom through a slot 16a in the panel I9, intothe registering slot I6 of the actuating plate, and is actuated eachtime an end of the arcuate slot I6 contacts the pin durin the turning ofthe actuating member by the handle 74. Another horizontal stud 95, fixedto the driven plate I5 projects through an arcuate slot 95 in the paneland is arranged alongsideof the pin 1 3 of the actuating plate.

A coil spring 91 surrounds the pivot bolt II and has its end portionscrossed at 98, and its legs 99 and I 98 arranged at opposite sides ofthe pins I3 and 99, so that the spring will be tensioned when one of thepins is moved relatively away from the other.

A driven rod IEJI, which may be formed of parallel plates, has a rollerI82 at its upper end movable in a cam slot I03 of the driven plate I5.Power is delivered by the driven member to the rod or link I by the camslot, and such slot is curved to give a variable mechanical advantage,so that high pressure is set up on electrical contacts I84 and I 95 bythe bridge I06 of the switch after the switch is closed (Fig. In thisfigure, the mechanism is shown for maximum pressure or while the switchis in the on position. Of course, the bridge I88 is carried by the linkIOI. A swinging link ID'I is pivotally connected at one end to the axleofthe roller I02, and is pivotally connected, at its opposite end to afixed stud I 98, projecting from the front of the panel I0.

In the operation of this modification, it may be seen from Fig. 8 thatif handle M is depressed to cause the driving member I2 to moveclockwise, the pin '53 will move the leg I80 of the spring 91 downwardlyso as to tension that spring, and as soon as the lower end of thearcuate slot I8 of the driv ng member I2 contacts the pin 94, the latterwill move with the driving member in a clockwise direction about theaxis of the bolt II As the stud S4 is fixed to the three-armed lever,the latter will turn in a counter-clockwise direction about the axis ofthe pin 9 so as to shift the toggle links 8?, 39 until the three-armedlever moves over dead center, at which time the spring 93 will functionto shift it from the position shown in Fig. 8 to the position shown inFig. 5, and as the pin I9 connects the three-armed lever to the drivenplate IS, the latter will be moved clockwise, under the influence of thespring 91, so as to cause the cam slot I03 to lift the link IUI tocompel the bridge I86 to engage the contacts I04 and I05, as shown inFig. 5.

When the parts are in the position shown in Fig. 5, they may be returnedto the position shown in Fig. 8 by movingthe handle I4 upwardly.

From the foregoing, it is believed the construction, operation andadvantages of the invention may be readily understood, and it isapparent that changes may be made in the details disclosed withoutdeparting from the spirit of the invention, as expressed in thefollowing claims.

What I claim and desire to secure by Letters Patent is:

1. In a switch of the character described, a double toggle including athree armed intermediate lever and a pair of links, one end of one linkbeing turnable about a fixed axis and having its other end pivotallyconnected to an arm of the three-armed lever, the other link having oneof its ends turnable about a fixed axis and its other end pivotallyconnected to an opposite arm of the three-armed lever, spring meansoperatively connected to the remaining arm of the threearmed lever andadapted to yieldingly hold the latter in either One of two positions, anactuator operatively connected with the double toggle for initiatingmovement of the three-armed lever into either one of its two positions,a second spring means operatively connected to the actuator, anoperating member for moving the actuator and tensioning the secondspring means, a driven member actuated by the second spring means, and acontact actuator driven by said driven member.

2. In a switch of the character described, a double toggle including athree-armed intermediate lever and a pair of links, one end of one linkbeing turnable about a fixed axis and having its other end pivotallyconnected to an arm of the three-armed lever, the other link having oneof its ends turnable about a fixed axis and its other end pivotallyconnected to an opposite arm of the three-armed lever, spring meansoperatively connected to the remaining arm of the three armed lever andadapted to yieldingly hold the latter in either one of two positions, apivotally mounted actuator cperatively connected with the double togglefor initiating movement of the three-armed lever into either one of itstwo positions, a second spring means operatively connected to theactuator, an operating member for turning the actuator and tensioningthe second spring means, a driven member actuated by the second springmeans, and a contact actuator driven by said driven means.

.3. In a switch of the'character described, a double toggle including athreearmed intermediate lever and a pair of links, one end of one linkbeing turnable about a fixed axis and having its other end pivotallyconnected to an arm of the three-armed lever, the other link having oneof its ends turnable about a fixed axis and its other end pivotallyconnected to an opposite arm of the three-armed lever, spring meansoperatively connected to the remaining arm of the three-armed lever andadapted to yieldingly hold the latter in either one of two positions, apivotally mounted actuator operatively connected with the double togglefor initiating movement of the three-armed lever into either one of itstwo positions, a second spring means operatively connected to theactuator, an operating member for turning the actuator and tensioningthe second spring means, a driven member actuated by the second springmeans and pivotally mounted for movement about the same axis on whichthe actuator .turnsyand a contact carrierdrivenyby said driven member.

4. In a switch of the character described, a-

double toggle including a three-armed intermediate lever and a pair oflinks, one end of one link being turnable about a fixed axis and havingits other end pivotally connected to an arm of the three-armed lever,the other link having one of its ends turnable about a fixed axis andits other end pivotally connected to an opposite arm of the three-armedlever, spring means oneratively connected to the remaining arm of thethree-armed lever and adapted to yieldingly hold the latter in eitherone of two positions, an actuator operatively connected. with the doubletoggle for initiating movement of the three-armedlever into either oneof its two positions, a second spring means operatively connected to theactuator, anoperating member for moving the actuator and tensioning thesecond spring means, a driven member actuated by the second springmeans, and a contact carrier cperatively connected to the three-armedlever and -1noved thereby.

5. In a switch of the character described, a double toggle including athree-armed intermediate lever and a pair of links, one end of one linkbeing turnable about a fixed axis and having its other end pivotallyconnected to an arm of the three-armed lever, the other link having oneof its ends turnable about a fixed axis and its other end pivotallyconnected to an opposite arm of the three-armed lever, spring meansoperatively connected to the remaining arm of the three-armed lever andadapted to yieldingly hold the latter in either one of two positions,said three-armed lever being provided intermediate its opposed arms withan elongated slot, a pivotally mounted actuator for initiating movementof the three-armed lever into either one of its two positions, a pinpivotally mounted in the actuator and having a flat head slidablymounted in said slot, a second spring means operatively connected to theactuator, an operating member for rotating said actuator and tensioningthe second spring means, a driven member actuated by the second springmeans, and a contact actuator driven by said driven member.

6. In a switch of the character described, a

double toggle including a three-armed intermediate lever and a pair oflinks, one end of one link being turnable about a fixed axisand havingits other-end pivotally connected to an arm of the three-armed lever,the other link having one of its ends turnable about a fixed axis andits other end pivotally connected to an opposite arm of the three-armedlever, spring means oper-atively connected to the remaining arm of thethree-armed lever and adapted to yieldingl hold the latter in either oneof two positions, a pivotally mounted actuator operatively connectedwith the double toggle for initiating movement of said lever into eitherone of its two positions, a second spring means operatively connected tothe actuator, an operating member for turning the actuator andtensioning thesecond spring means, a pivotally mounted driven memberactuated by the second spring means and provided with guiding meanshaving a portion tangent to the axis of rotation of the driven member,and a contact actuator operatively connected to said guide, means andactuated by said driven member.

7. In a switch of the character described, a double toggle including athree-armed intermediate- 8" lever anda pair of links, one endof onelink being turnable about a fixed axis and having its other endpivotally connected to an arm of the three-armed lever, the other linkhaving one of its ends turnable about a fixed axis and its meansoperatively connected to the actuator, an'

operating member for turning the actuator and tensioning the secondspring means, a driven member actuated by the second spring means andturnable about the same axis as the actuator, said driven member havinga tangentially arranged slot, a roller travelling in said slot, and

a contact actuator connected to the roller and driven by the drivenmember.

8; In a switch of the character described, a

supporting panel, a manually controlled mechanism supported by saidpanel and arranged at one." side thereof, a contact actuator having anend portion pivotally connected to said mechanism andoperated thereby, asupport pivotally mounted on the opposite side of said panel, saidpanel, being provided with an aperture between the point where thesupport is pivotally mounted and the place where the contact actuator ispivotally connected to said mechanism, a trigger connecting the medialportion or the actuator to said support and extending through saidaperture, resilient means connected to the support for constantly urgingthe contact actuator into openswitchposition, and thermostatic meansengageable with the trigger and responsive to a condition' in thecircuit controlled, to prevent the contact actuator from moving inresponse to said resilient means.

9. In a switch of .the character described, a manually controlledmechanism, a contact actuator pivotally connected thereto, a rodslidably supported by the actuator, a bridge slidably mounted on therod, stationary contacts with which the bridge' cooperates to complete acircuit, a spring mounted on the rod and arranged to be compressed whenthe bridge engages the con-- tacts for yieldingly pressing the bridgeagainst said contacts, resilient means constantly urging the contactactuator and bridge into open-switch position, and thermostatic means inelectrical connection with one of said contacts and responsive to acondition in the circuit controlled, to prevent said actuator frommoving in response to said resilient means.

FRANK A. TALBOT.

REFERENCES CETEI) The following references are of record in the

